The present invention generally relates to rotary tools and more particularly relates to a quick-release chuck having an axially slidable member to actuatably release or hold a tool bit.
Chucks for rotary tools are generally known. A chuck is securable to a rotatable shaft of a power tool and is operable to hold a replaceable tool bit. Known quick-release chucks have a bore in which a tool bit is received, and the chuck includes a locking element which is selectively actuatable to secure or release the tool bit.
Conventional quick-release chuck structures have implemented components which occupy a significant axial length. It is desirable to provide a chuck that has a low-profile, compact structure with a minimal length.
At least some conventional quick-release chucks have a configuration such that, when mounted to a rotatable shaft of a power tool, a significant gap exists between the chuck and a housing of the power tool. It is desirable to minimize the gap for safety and compactness.
Also, conventional chucks have included a large number of components, requiring a complex and expensive assembly process. Accordingly, a need exists for an improved chuck that has few components and is relatively easy to assemble. SUMMARY OF THE INVENTION
The present invention provides an improved quick-release chuck having a compact profile and view components. In an embodiment, the chuck includes a barrel configured to be mounted to a rotatable shaft of a rotary power tool. The barrel has an axial bore for receiving and holding a tool bit. A moveable sleeve fits concentrically around the barrel and is axially moveable relative thereto for actuating one or more locking member, such as a radially-moveable ball positioned in a hole through the barrel to releasably secure the tool bit in the bore. To release the locking member, the moveable sleeve is axially retractable toward the power tool. The chuck additionally includes a collar which has a low-profile shape. In particular, the collar has a central flange which is disposed around the barrel, a planar web portion which extends radially outwardly from the central flange and an outer guide flange that extends from an outer periphery of the planar portion in a direction away from the rotary power tool. The outer guide flange is shaped to receive and guide a proximal portion of the moveable sleeve when the sleeve is pulled to release the tool bit. The outer guide flange also serves to cover a gap between a proximal side of the moveable sleeve and the planar web portion of the collar. The collar is secured to the barrel in a position closely proximal to the power tool housing. The structure of the collar minimizes the gap between the chuck and the housing of the rotary power tool, advantageously enhancing safety and minimizing the necessary length of the chuck.
In an embodiment, a distal end of the barrel includes a radially projecting shoulder to limit the axial travel of the moveable sleeve. The collar is concentrically positionable around a proximal end of the barrel, capturing a compressible spring or other biasing member between the moveable sleeve and the collar. The collar is preferably secured by a retainer ring received within a detent of the barrel against a proximal side of the collar.
In an embodiment, the moveable sleeve, spring, collar, and retainer ring are easily assembled onto the barrel in a stackable manner from the proximal end of the chuck. The collar acts as a cap which compresses the biasing member and effectively holds the components of the chuck in an assembled condition. The stackable configuration advantageously facilitates an assembly of the chuck in a simple and efficient manner.
These and other features and advantages of the present invention are described in, and will be apparent from the following description, claims and figures.